But the date is just the beginning for Harrison, 47, who tells PEOPLE, "She's sticking me with all the planning!"

The nuptials – initially planned for Las Vegas – will now take place at the Ritz Carlton in Southern California's Laguna Beach.

"It will be a lot of friends and family," Harrison said while attending Wednesday night's opening of Wynn Las Vegas's Andrea's. "It started off with about 40 people and it's well over 100 people now. You know how those things go."

Aside from the guest count close to being finalized, Harrison said Danny Koker of the History Channel's Counting Cars will become an ordained minister and marry the couple, and Harrison's Pawn Stars costar Chumlee is set to be the ring bearer.

"I can't make that up," he said. "I just had no idea there was so much involved. I just thought you got a cake, had a party, buy a keg. But we're getting it done."